Freestanding Units
If you are working with a "freestanding" cupboard that is not fastened to the wall, your problem could be that the cabinet is racked out of kilter. Push on the top left or right side of the unit and see if it helps the situation any. If it does, you will need to place shims underneath the bottom of one corner of the cabinet. This is going to be a process of trial and error to get the unit situated correctly. If it is setting on carpet, the culprit may be the tack strip that is installed right next to the wall.

The Entire Edge of the Door Sticks Past the One Next to it
Another possible situation might be that when the cabinet door is closed it has a tendency to slightly reopen along the entire edge of the door. If this is the case, both hinges may need to be adjusted toward you, away from the cabinet face. What is happening is the inside of the door is binding on the cupboard face and will not allow it to close completely.

A couple of years ago, the Blum company had a defective piece that would go bad on their concealed European hinges after about five to ten years of use. It was noticeable by the clicking sound that was made every time the door was opened or closed. The doors would often be very difficult to close or open as well. Luckily for many homeowners, the hinges have a lifetime guarantee. The company has since corrected the problem.